One of the several methods of removing malodorous elements of air from bathrooms is the use of exhaust fans. Fans, mounted on a wall or in the ceiling, vents malodorous bathroom air to the outside environment. During the exhaust period however, the migration of malodorous air throughout the bathroom becomes unpleasant to both the current and subsequent bathroom users.
In some prior art devices, such as in U.S. Pat. No. 2,227,920 issued January 1941 to Baither, the odor removal device is not an attachment, rather, it is an integral part of the design of the commode, and thus it is not suitable as an attachment to a commode of a different design.
In other prior art devices, alteration of the bathroom wall is required so that the malodorous air can be vented directly from the bowl to the atmosphere through an air duct. Examples of such devices are described in:
U.S. Pat. No. 2,100,962 issued, Nov. 19, 1937 to Juntunen; PA1 U.S. Pat. No. 2,105,794 issued January, 1938 to Norris; PA1 U.S. Pat. No. 2,279,789 issued April, 1942 to Jentzer; PA1 U.S. Pat. No. 2,881,450 issued March, 1959 to Tubbs; PA1 U.S. Pat. No. 4,165,544 issued August, 1979 to Barry; PA1 U.S. Pat. No. 4,175,293 issued November, 1979 to Stephens; PA1 U.S. Pat. No. 3,691,568 issued September, 1972 to Martz. PA1 U.S. Pat. No. 3,763,505, issued to Zimmerman, Oct. 9, 1973 PA1 U.S. Pat. No. 4,583,250, issued to Valarao, Apr. 22, 1986 and PA1 U.S. Pat. No. 3,781,923 issued to Maisch, January, 1974. PA1 (a) to expel the column of water disposed in the submerged is line 16, shown in FIG. 2 of U.S. Pat. No. 4,590,629, issued May 27, 1986, to Lusk, the required pressure being at least equal to the weight of water disposed in line 16, PA1 (b) to force the water through the relatively high impedance of the diffuser. PA1 (a) overcome the air leakage between the user and the seat, and, PA1 (b) overcome the leakage of ascending malodorous air from the bowl during and after the deposition of waste into the bowl.
Large area, flat type charcoal filters are used in devices which are mounted on the top of existing flushing tanks such as described in:
Described in U.S. Pat. No. 4,590,629, issued May 27, 1986, to Lusk, is a pump for pumping air from a toilet bowl through a diffuser which is submerged in the flushing tank water. Since an under-water diffuser presents a higher impedance to air flow rate sufficiently high to overcome both the escaping, ascending, than a porous filter, higher air pressure is required; thus, a pump is appropriate. However, such a pump is also required to have an air flow rate sufficiently high to overcome both the escaping, ascending, air from the bowl and the leakage of air between the seat and the bowl. Contrary to the requirement of both high air pressure and high air flow rate, porous filter type malodorous air element removers require lower air pressure with the same air flow rate; thus, simple fans or blowers are adequate.
There are at least two requirements of the pump used in diffuser type devices:
1. The pump must be capable of providing sufficient pressure to:
2. The pump must have an air-flow rate sufficiently high to:
Reference is made to vibrator type pumps, used for aerating small fish tanks. Pumps of this type can produce adequate pressure for the small air-flow rate required for small fish tanks; however, the low air-flow rate would result in the removal of an unacceptable amount of malodorous air from the bowl in the device described in the Lusk U.S. Pat. No. 4,590,629.
The above indicated combined requirements of air pressure, and the electrical power necessary to operate such a pump, is inconsistent with the use of a battery located inside the tank. A battery of acceptable size would have inadequate life; and alternatively, a battery with an acceptable life expectancy would be of a size unsuitable for mounting inside the tank; thus, AC line power, as suggested, would be used. However, the electrical shock hazard of using AC line power devices in the bathroom environment is well known. In the case of Lusk U.S. Pat. No. 4,590,629, the proximity of the AC motor to the ground potential of the flushing tank shown in the drawings, make the hazard evident and inconsistent with many building codes.
U.S. Pat. No. 4,726,078, issued Feb. 23, 1988, to Carballo, teaches a ventilating toilet seat which replaces the original seat. The replacement seat comprises a pre-filter for providing a scenting means for deodorizing noxious air. Air is extracted from the seat, through a tube or hose, by a separate fan or blower unit located adjacent to the toilet seat. Although devices of this type are attachable, the inconvenience and unsightliness of a hose attached to the seat, and the obstructive nature of the accompanying blower unit, are undesirable features.
Whether a seat-device mounted on the bowl, or a device attached to the top of the flushing tank, the attachment of these devices requires that the mating interfaces of the device and commode be such that a proper seal is maintained. The lack of an industry standard, for the shape and size of tanks and bowls, places a burden on the potential suppliers of such devices. A supplier of such devices would necessarily have the additional cost of designing, manufacturing and marketing many models of different sizes and shapes. This design of multiple products is necessary if the device is to be compatible with the majority of prevailing commode flushing tanks and seats.
A further undesirable feature of these add-on devices is their perceived intrusion into the bathroom. Their high visibility and their effect on the bathroom decor must also be a consideration in a potential product Some likely perceptions are that the height of the tank has been increased, or that there is a highly visible hose is attached to the seat, or that there is a highly visible line chord, of questionable safety, between the device and the electrical wall outlet. Another likely perception is that there is not an acceptable color match between the commode tank or bowl and the device. Color, as well as size and shape, is an important parameter in the visual acceptance of any bathroom device. In consideration of the many different colors of prevailing commodes, the matching of the color of the device with the color of the commode would be impractical. The cost to maintain a stock of the wide variety of the many different sizes, shapes and colors, required to match prevailing commode, renders these devices unfeasible with respect to cost, appearance, installation, serviceability and safety.